October 2011

2011-10-27: The review section now lets you mark posts as reviewed. Doing so allows you to directly take actions on these posts (such as voting, flagging, commenting, …), and hides them from the review section.

2011-07-16: Mobile theme for Stack Exchange sites launched. Users can switch back and forth from the mobile theme using the 'mobile' link at the bottom of every page.

2011-07-15: Anonymous and low rep (<15) users now see a "give feedback" link where logged in users usually see "add comment". When moused over, this shows "Was this post useful to you [yes] [no]". This is just for testing purposes right now - it does not affect the post's score.

2011-07-07: Migrating to another site requires 4 migration votes, instead of a simple 3/5 majority as before. This change applies only to Stack Overflow.

2011-07-06: Close- and reopen- votes now age away on a sliding window: if four days elapse without a close or reopen vote, the votes begin aging away. Posts with fewer than 100 views do not expire votes.

2013-11-07 (or earlier): when calculating the Gravatar email hash for those who do not have a Gravatar account, in some cases now a salt is used.

October 2013

2013-10-08: Deleted answers that have had any spam or offensive flags raised against them will not show the answer body but the following text: "This answer was marked as spam or offensive and is therefore not shown - you can see the revision history for details". Where "the revision history" links to the answer revision history. The vote box (with score) and comments will still appear. (source)

2013-10-07: In user history, Moderators can now see if a user is post-blocked, when, and if they've tried to post since being blocked. (source)

September 2013

2013-09-11: The dialog for flagging posts was redesigned in order to streamline the process. For example, the options for spam and offensive are now listed first. Also, duplicate votes are now separated from close votes.

August 2013

2013-08-12?: It is possible to see one's own deleted recent answers and questions. http://stackoverflow.com/users/recently-deleted-answers/<userID> and http://stackoverflow.com/users/recently-deleted-questions/<userID>. Linked from "answers" and "questions" tag in profile page.

July 2013

2013-07-29: All flags that appear in a user's flagging summary that are not yet dismissed by a moderator have the marking "active" in it. It appears to mean "awaiting attention by a moderator". Source.

2013-07-26: As a counter-measure against robo-reviewing, review ban times now automatically increase based on the amount of previous bans up to a maximum of 30 days.

2013-06-26: Flagging limits changes: You start with 10 flags per day, you can end up with as many as 100 per day. You get an extra flag per day for every 2000 reputation points or 10 net helpful flags (helpful-unhelpful).

April 2013

2013-04-23: Changes to the treatment of deleted content: Deleted questions will be visible to their authors, regardless of those authors' reputation; and delete-voting within two days of closing is disabled on questions scoring -2 or above, regardless of the voter's reputation.

2013-04-22: A new footer is implemented on all sites. It links to a new grid view of all Stack Exchange sites.

2013-04-02: Users are now shown a persistent (but dismissable) banner linking to /about on the site.

March 2013

2013-03-26: The Linked and Related lists on the right sidebar are now displayed with larger text and with the score for each question.

2013-02-18: The revision history of a question that was closed as a duplicate is now showing the chosen originals as part of the "Closed as duplicate" notice.

2013-02-11: If a visitor is not logged in or doesn't have enough reputation to vote, the vote system redirects the vote to the anonymous feedback system, and shows a small blue dialog.

2013-02-06: The auto inserted text for questions closed as duplicates has been changed to "This question already has an answer here:" followed by link to the other question and the number of answers it has. The text is no longer edited into the original question but rather displayed externally. While the question is still open, only the OP sees the message and it becomes visible to everyone once the question gets closed. Questions closed as duplicate prior to this change still have the old "Possible Duplicate:" text in them.

2013-02-01: The "close as duplicate" process has been updated: the interface to search for duplicate questions has been improved, and users may no longer vote to close questions as duplicates of questions that do not have an upvoted or accepted answer

January 2013

2013-01-22: Accept rates will no longer be shown. Like flag weight, they will continue to be calculated for backend use.

2013-01-22: A question closed as a duplicate now gets a " [duplicate]" appended to its title, rather than just " [closed]". It also shows "marked as duplicate" instead of "closed as…" in the post notice.

2013-01-10: First version of the new 'About' page rolled out to act as Quick Start guide for new users. New Bronze "Informed" badge for reading the entire page.

2013-01-04: A new elasticsearch-based search engine has been rolled out across the network. New features include multi-term searches defaulting to AND rather than OR, word stemming, excluded terms -term, infavorites: coming back, ranges for answers: and created: and score:, and more.

November 2012

October 2012

2012-10-19: Review actions limits have been changed: after 20 reviews in a given queue, you're done for the day - if you want to continue reviewing, you can switch to a different queue. Limit is doubled for queues with large backlogs.

2012-10-17: Reopen Votes review queue has been introduced to vote whether or not to reopen closed questions.

2012-10-16: The number of reviews required to accept/reject suggested edits has been increased to two network wide (versus one before) and three on Stack Overflow (versus two before). Moderators can still cast the final vote like before.

September 2012

2012-09-22: Voting allowed (and encouraged) in First Posts and Late Answers review queues.

2012-09-21: New badges added for completing community review tasks. User can earn Custodian (1 review), Reviewer (250 reviews) and Steward (1000 reviews) once for each review queue (Close Posts, First Posts, Late Answers, Suggested Edits and Low Quality Posts). The previous Reviewer badge (for reviewing posts in the old system) will no longer be awarded.

August 2012

2012-08-13: Review audits are introduced: known cases thrown into review queue as "gotchas" to keep people from just nailing "Looks Good" or "Close" or whatever without reading the posts.

July 2012

2012-07-13: The Help Center has been added. It contains pages for many common issues, offering suggestions and a form to email the team as needed. This is the new target of the "contact us" link in the footer, which was previously an email link.

2012-02-27: Reputation changes are kept up to date, without the need for a manual recalc. (Sync takes up to 5 minutes on a delete/undelete action.)

2012-02-22: Automatic question banning calculation has been changed on Meta to better reflect the idea that downvotes can be much more common on meta, for reasons that aren't necessarily related to quality of the post.

2012-01-20: Flag weight was removed from user profiles. Users having flags now see a "helpful flags" count on their own profile linking to the flag audit page, which now contains a breakdown of flag outcomes by flag type (moderator attention, spam, offensive, comment). The Deputy and Marshal badges were modified to require a number of helpful flags (80 and 500, respectively) instead of a specific flag weight.

2012-01-20: "very low quality" flags now carry an automatic downvote from the Community user with them, and are dismissed when the post is edited.

2012-01-16: The populist badge will no longer be awarded for self-answers. Also note that losing your qualification for a already-earned badge will (usually?) no longer result in your next badge of the same type being withheld.

June 2014

2014-06-10: When moderators or users with the "create new tags" privilege attempt to create one or more new tags either while asking a question or during an edit they are shown a confirmation dialog to reduce risk of tags created by mistake. This feature is enabled on a per-site basis.

May 2014

2014-05-19: Easy close review queue filtering interface - currently enabled only on Stack Overflow, with a threshold 50 for how many outstanding reviews there must be with a tag or close reason in order for it to show up on the dashboard.

May 2011

2011-05-16: Similar Questions are now shown when composing a question, based on the question title, body and tags. This is similar to the “Related” questions in the side bar after posting the question.

2011-05-16: When a bounty is started by the question owner and the owner accepts an answer during the bounty period, the full bounty will be awarded to that answer unless the owner explicitly gives it to another answer before the bounty expires.

2011-05-12: Quality filters are now applied to questions. (Here are two 10K only links.)

2011-05-12: Question downvotes are "free" to the downvoter and will not be subject to a -1 rep penalty. Downvotes to answers are unaffected and still "cost" 1 reputation to cast.

2011-04-14: Daily number of close votes on all Stack Exchange sites have been increased from 12 to 24, and 50 on Stack Overflow.

2011-04-14: Questions closed as “not a real question” and “off topic” get an automatic downvote (excluding questions that get migrated elsewhere).

2011-04-11: Questions with enough answers to push them into CW will have the new answer field replaced by an "Answer This Question" button, which asks the user to read through the existing answers first to make sure the new answer isn't a duplicate.

2011-04-10: Migrated questions now show [migrated] instead of [closed].

2011-04-09: New users (<100 reputation) can no longer answer their own question within 8 hours.

2011-04-08: Votes that were undone (revoked within the undo window) are no longer locked in; one can now come back later to cast a new up/down vote.

2011-04-08: New answerers (<100 reputation) get dynamic help when focusing the answer box.

Feb 2011

2011-02-22: Requirements for achieving the Strunk & White and Copy Editor badges have changed. Now it only counts how many revisions are made, not individual title or body changes. Each requires 80 and 500 revisions respectively.

2011-02-09: Flagging for moderator attention now counts for the Citizen Patrol badge. This change applies retroactively.

2011-02-09: Privilege changes: Create tags has been raised from 150 to 300. Retag has been raised from 200 to 500. A new 5k privilege to approve or reject tag wiki edits has been added. A new 15k privilege to protect a question has been added. The question must be older than a day. You can also un-protect a question you protected, but not one that has been protected by someone else. The requirements for editing a tag wiki have been simplified to a 20k rep privilege.

2011-01-27: Area 51 gets an updated design, proposal categories, and a discussion zone. A51 posts are now oneboxed in chat.

2011-01-27: Stack Exchange now uses Lucene instead of SQL Fulltext for search, related questions, and the 'similar questions' in Ask a Question. Option infavorites is no longer supported, some search keys like intitle have changed names, and a new option body is introduced. See the help on the /search pages.

2011-01-14: Tag pop-ups now lists "Followers" which is equal to the number of people who have favorited (marked as interesting) the tag and the number of email subscribers. Subscribing to RSS is not tracked.

2011-01-13: Flag dialog improved. Its "flag for moderator attention" option now provides several default reasons, where appropriate: "not an answer", "low quality" and "should be CW". It allows for longer messages to a moderator. The daily maximum number of flags has been increased. And if a particular user keeps moderator flagging for reasons that are considered invalid, their flag weight decreases. And for those users who continually flag reliably, their flag weight increases.

2011-01-11: Authors can now only delete their question if it has zero answers, or only one answer with zero score. In all other cases, voting or flagging is required.

2011-01-08: The "flags" tab in 10k tools was improved; it now shows comment flags in addition to spam/offensive flags, and lets users display the entire post and add their own flag directly from the flags tab. It also preserves the other mod tool tabs.

2011-01-08: When hovering over any tag (like this one: stackoverflow) a pop-up will appear. From this you can subscribe to email notifications, add the tag to your RSS reader and view the tag wiki excerpt. Where no tag wiki is available an invitation to create the tag wiki appears. The pop-up also includes links to the FAQ, Info & Top Users pages for the tag.

2011-01-07: Chat "whitelists" no longer allow specified users to talk regardless of their rep. Users with less than 20 rep now get only four hours of chat time before being locked out.

2010-12-12: To make the code highlighting work better, it now uses the question tags to guess what language is used in both the question and its answers. When no guess can be made, or on sites on which highlighting makes little sense (Super User, photo.stackexchange.com, ...) no highlighting will be used.

2010-12-11: New badges for posting in Meta sites:
Quorum (bronze) for one post with score of 2 on meta, and Convention (silver) for 10 posts with score of 2 on meta.

2010-12-10: User profiles now display the user's tag statistics (number of questions asked and answers given, along with total question score and total answer score) for each tag on the stats tab. Tooltip gives full details.

Nov 2010

2010-11-24: Mouseover of chat messages now highlights any replies to that message.

2010-11-13: The "activity" tab of the user profile now gives the option to dynamically show the content of recently posted answers.

2010-11-09: Questions are now sorted by "amount of interest" on the homepage rather than time of last activity. (Stack Overflow only.)

2010-11-08: The frequency of the notification envelope lighting up has been toned down in favor of the global inbox.

2010-11-07: Behavior of [tag:tags] on meta sites updated to refer to the parent site by default; new syntax introduced for a meta-site's own tags (source).

2010-11-07: Support for the <kbd> tag re-enabled on Meta Stack Overflow.

2010-11-05: Posting links to the very same site now automatically shows the title. So, just insert http://meta.stackexchange.com/questions/59445/whatever. to become Recent feature changes to Stack Exchange. The title is not shown in the preview, but inserted when the post is created or edited. The title is not updated when it changes, unless the post is edited. It does not work in comments, nor for links to other SOFU sites. Trailing punctuation marks such as a comma, dot or question mark (without URL parameters) to get a readable sentence work just fine.

Aug 2010

2010-08-17: hot questions formula has been tweaked: Succeeding questions from the same site are penalized by increasing amounts. Community wiki questions are penalized. The benefit of many answers is capped at 10, and we only look at the score of the top 3 answers. We only degrade based on question age, and not the last update date on a question.

2010-08-10: Questions from IP addresses or accounts with a history of extremely poor questions are no longer being accepted. Votes on questions are taken into account, and this yields a permanent IP ban, showing "Sorry, we are no longer accepting questions from this account".

2010-06-19: Complete overhaul of the bounty system. Any user with sufficient reputation can start a bounty on any question. A question may have multiple bounties, though only one active bounty is allowed at any given time. Bounty awards are no longer tied to accepted answer in any way. But the system no longer tosses in +50 bonus reputation to a bounty. (More rules.)

2010-06-13: SEDE, Stack Exchange Data Explorer, which for SO also "can be used as a permanently linkable tool for teaching general SQL and relational database concepts — we can be our own Northwind or Pubs database, when answering questions tagged [sql]". (Since December 2010, its URL is data.stackexchange.com.)

2010-05-10: Replying to @françois and @jørn can nowalso be done using @francois and @jorn.

2010-05-09: Reputation report improved, now you can check rep-cap status from purely upvotes (reached) and upvotes + accepts (exceeded). Note that bounties are not included on any of that. And Epic/Legendary badges calculation based on exceeded.

2010-05-08: Search now supportsinquestion:this to limit the search to the current question (using the referrer as sent by your browser).

Apr 2010

2010-04-30: The vote-undo locked text was changed into a more specific "You last voted on this question / Mar 28 at 7:55 / Your vote is now locked in / unless this question is edited", hence also allowing you to see when you voted if your memory fails you.